Charles R. Powell

Long-Term Outcomes of Urgency-Frequency Syndrome Due to Painful Bladder Syndrome Treated With Sacral Neuromodulation and Analysis of Failures

PURPOSE We present our long-term experience with sacral neuromodulation devices placed in patients with painful bladder syndrome to determine whether the benefit decreases over time. MATERIALS AND METHODS Between January 2000 and July 2004, 32 women and 7 men with interstitial cystitis/painful bladder syndrome in whom previous conventional therapy failed underwent sacral neuromodulation test stimulation. Before 2003 a percutaneous test lead was placed in the clinic setting. After 2003 a quadripolar permanent lead was placed in the operating room. Permanent generators were implanted if the patient had more than 50% relief from the presenting complaint, which was defined as urinary or pelvic pain, urgency, or urinary frequency. Long-term outcomes included battery depletion, device malfunction, infection or loss of benefit as well as any change in need for medications. RESULTS Of 39 patients 22 went from test stimulation to permanent generator implantation. There were significant differences in short-term but not long-term outcomes between the 2 methods of test stimulation. Of 33 patients undergoing percutaneous nerve evaluation 13 (39.4%) met the criteria for permanent generator implantation, while 9 of 11 (81.8%) evaluated with the quadripolar lead met these criteria (p = 0.015). Long-term success between the groups was similar at 92.3% (12 of 13) vs 77.8% (7 of 9) (p = 0.329) during an average followup of 59.9 months. Eleven (50.0%) devices required explantation. Of 22 patients 3 (13.6%) lost benefit over time. CONCLUSIONS These patients appear to respond best to permanent quadripolar lead placement but long-term results do not appear to be independently affected by the method of test stimulation. Loss of benefit over time is not common.

Outcomes of lung transplantation in patients with scleroderma

Patients with pulmonary insufficiency due to scleroderma have long been considered suboptimal candidates for lung transplantation. This has been supported by small single-center experiences that did not reflect the entire U.S. experience. We sought to evaluate the outcome of patients with scleroderma who underwent lung transplantation. We conducted a retrospective review of 47 patients with scleroderma who underwent lung transplantation at 23 U.S. centers between 1987 and 2004 and were reported to the United Network for Organ Sharing. Women constituted 57% of the patients. The mean age was 46 years. Twenty-seven patients received single lung transplants (57%), and the remaining received double lung transplants. The mean cold ischemia time was 4.1 hours. There were 7 early deaths (≤30 days) and 17 late deaths (> 30 days). The causes of early death were primary graft failure and a cardiac event in two patients each and bacterial infection and stroke in one patient each. Late mortality was due to infection in seven patients, respiratory failure in three, malignancy in two, and multisystem organ failure, rejection, pulmonary hypertension, and a cardiac event in one patient each. The causes of early and late death were not recorded for two patients. One patient received a second transplant owing to graft failure of the first. Twenty-three patients (49%) were alive at a mean follow-up of 24 months. The Kaplan-Meier 1- and 3-year survival rates were 67.6% and 45.9% respectively, which are not significantly different from those of 10,070 patients given transplants for other lung conditions during the same period (75.5% and 58.8% respectively, P = 0.25). Donor gender, recipient’s age, and type of transplant did not affect survival. In carefully selected patients with scleroderma who have end-stage lung disease, lung transplantation is a valid life-saving therapeutic option. Available data suggest acceptable short-term morbidity and mortality and a long-term survival similar to that of patients given transplants for other lung conditions.

Contribution of Renal Innervation to Hypertension in Rat Autosomal Dominant Polycystic Kidney Disease

The kidney has both afferent (sensory) and efferent (sympathetic) nerves that can influence renal function. Renal innervation has been shown to play a role in the pathogenesis of many forms of hypertension. Hypertension and flank pain are common clinical manifestations of autosomal dominant (AD) polycystic kidney disease (PKD). We hypothesize that renal innervation contributes to the hypertension and progression of cystic change in rodent PKD. In the present study, the contribution of renal innervation to hypertension and progression of renal histopathology and dysfunction was assessed in male Han:SPRD-Cy/+ rats with ADPKD. At 4 weeks of age, male offspring from crosses of heterozygotes (Cy/+) were randomized into either 1) bilateral surgical renal denervation, 2) surgical sham denervation control, or 3) nonoperated control groups. A midline laparotomy was performed to allow the renal denervation (i.e., physical stripping of the nerves and painting the artery with phenol/alcohol). Blood pressure (tail cuff method), renal function (BUN) and histology were assessed at 8 weeks of age. Bilateral renal denervation reduced the cystic kidney size, cyst volume density, systolic blood pressure, and improved renal function (BUN) as compared with nonoperated controls. Operated control cystic rats had kidney weights, cyst volume densities, systolic blood pressures, and plasma BUN levels that were intermediate between those in the denervated animals and the nonoperated controls. The denervated group had a reduced systolic blood pressure compared with the operated control animals, indicating that the renal innervations was a major contributor to the hypertension in this model of ADPKD. Renal denervation was efficacious in reducing some pathology, including hypertension, renal enlargement, and cystic pathology. However, sham operation also affected the cystic disease but to a lesser extent. We hypothesize that the amelioration of hypertension in Cy/+ rats was due to the effects of renal denervation on the renin angiotensin system.

Sacral neuromodulation in diabetic patients: Success and complications in the treatment of voiding dysfunction†‡

We compared success rates, subsequent complications, and possible indications for success of sacral neuromodulation (SNM) for urinary voiding dysfunction in diabetic and non‐diabetic patients.

An Implantable Pressure Sensing System With Electromechanical Interrogation Scheme

In this paper, we report on the development of an implantable pressure sensing system that is powered by mechanical vibrations in the audible acoustic frequency range. This technique significantly enhances interrogation range, alleviates the misalignment issues commonly encountered with inductive powering, and simplifies the external receiver circuitry. The interrogation scheme consists of two phases: a mechanical vibration phase and an electrical radiation phase. During the first phase, a piezoelectric cantilever acts as an acoustic receiver and charges a capacitor by converting sound vibration harmonics occurring at its resonant frequency into electrical power. In the subsequent electrical phase, when the cantilever is not vibrating, the stored electric charge is discharged across an LC tank whose inductor is pressure sensitive; hence, when the LC tank oscillates at its natural resonant frequency, it radiates a high-frequency signal that is detectable using an external receiver and its frequency corresponds to the measured pressure. The pressure sensitive inductor consists of a planar coil (single loop of wire) with a ferrite core whose distance to the coil varies with applied pressure. A prototype of the implantable pressure sensor is fabricated and tested, both in vitro and in vivo (swine bladder). A pressure sensitivity of 1 kHz/cm

Buccal mucosal graft urethroplasty in the treatment of urethral strictures: experience using the two-surgeon technique.

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Treatment of Bladder Diverticula, Impaired Detrusor Contractility, and Low Bladder Compliance

O is achieved with minimal misalignment sensitivity (26% drop at 90° misalignment between the implanted device and acoustic source; 60% drop at 90° misalignment between the implanted device and RF receiver coil).

Conditional Electrical Stimulation in Animal and Human Models for Neurogenic Bladder: Working Toward a Neuroprosthesis

At our institution, the majority of buccal mucosal graft urethroplasties are performed using a two-team approach with an otolaryngologic surgeon. We report our two-surgeon experience with buccal mucosal grafting for reconstruction of all anterior urethral strictures. Twenty-four men underwent autologous buccal mucosal graft urethroplasty between October 2001 and September 2008 for recurrent urethral stricture disease. Twenty-two underwent a single-stage repair and two underwent a two-stage repair. Medical charts were retrospectively reviewed for demographics, comorbidities, etiology, location and length of stricture, and prior interventions in order to identify predictors of buccal urethroplasty success, defined as no evidence of stricture recurrence. All patients underwent retrograde urethrogram and cystoscopy. Operative and anesthesia times were evaluated. We determined an overall success rate of 83.3% (20 of 24 cases). Mean anesthesia time for single-stage urethroplasty was 155 min and mean operative time was 123 min. One of the two two-stage urethroplasties experienced stricture recurrence (50%). The single-stage buccal graft success rate was 86.4% (19 of 22 cases). Two of the four who developed recurrent stricture disease that required intervention had undergone a previous mesh urethroplasty. Complications developed in four of 24 patients (16.6%), including superficial wound infection (one), superficial wound dehiscence (two), and abscess/fistula formation requiring reoperation (one). The buccal mucosa is an ideal tissue for both single- and two-stage substitution urethroplasty for patients with recurrent stricture disease. Our two-surgeon technique minimizes anesthesia and operative times, and contributes to the overall high success rate and relatively low complication rate.

Sacral Neuromodulation for Refractory Urge Incontinence Is Less Effective Following Spinal Surgery

Bladder diverticula are common enough to be encountered by most urologists in practice but are reported less frequently in the literature than they were 50 years ago. Some patients can be managed nonoperatively, whereas others will need surgical intervention consisting of bladder outlet reduction and possibly removal of the diverticulum itself. In addition to the decision to operate, the timing of each intervention deserves careful consideration. Cystoscopy, computed tomography with contrast, urodynamic studies, cytology, and voiding cystourethrography play important roles in informing the clinician. Many new techniques for treatment of the bladder outlet and the diverticulum are available, such as laparoscopy and robotic surgery.

Traumatic Urethral Injury without Pelvic Fracture in an Adult Female

Sacral neuromodulation has had a tremendous impact on the treatment of urinary incontinence and lower urinary tract symptoms for patients with neurologic conditions. This stimulation does not use real-time data from the body or input from the patient. Incorporating this is the goal of those pursuing a neuroprosthesis to enhance bladder function for these patients. Investigators have demonstrated the effectiveness of conditional (also called closed-loop) feedback in animal models as well as limited human studies. Dorsal genital nerve, pudendal nerve, S3 afferent nerve roots, and S1 and S2 ganglia have all been used as targets for stimulation. Most of these have also been used as sources of afferent nerve information using sophisticated nerve electrode arrays and filtering algorithms to detect significant bladder events and even to estimate the fullness of the bladder. There are problems with afferent nerve sensing, however. Some of these include sensor migration and low signal-to-noise ratios. Implantable pressure sensors have also been investigated that have their own unique challenges, such as erosion and sensor drift. As technology improves, an intelligent neuroprosthesis with the ability to sense significant bladder events and stimulate as needed will evolve.